'METHOD AND DEVICE FOR ANALYZING THE ASH OR MINERAL CONTENT OF COAL'

摘要

The concentration of ash or mineral matter in coal is determined from: measurement of the intensity of X-rays or low energy ???-rays scattered in said coal in a first energy region so chosen that there is significant difference in absorption of radiation per unit weight in coal matter and mineral matter excluding iron, combined with further measurement of X-rays or low energy ???-rays scattered in said coal in a different energy region so chosen that there is a significant difference in absorption of radiation per unit weight of coal matter and mineral matter, the relative absorption per unit weights by said coal matter and said mineral matter at one energy region being significantly different from that at the other. Scattered X- or ???-rays from a radioisotope source 3 or several sources are scattered by coal 1 on a moving belt 2 and detected by scintillation counter 5 positioned either above the belt, with a lead shield 11 to prevent direct rays reaching the counter, or below the belt (not shown). Two single channel analysers 8 are interfaced at 9 with a computer 10 for calculating the ash content. IMAGE